This invention relates to the field of power dividers and, more specifically, to the use of such dividers with radio frequency (RF) power sources.
Power control systems which deliver input RF power to several output ports are typically very lossy. Many of such systems use transformers and transmission lines coupled to absorptive attenuators. Unfortunately, these systems do not deliver a large amount of their input power to their output ports, so such systems are not power efficient. Furthermore, many of these systems deliver power to output ports which have been turned off, which wastes power and makes it unavailable for other output ports.
For example, U.S. Pat. Nos. 4,028,632, 3,986,147 and 3,928,804 to Carter et al describe systems having an N-port circulator and isomismatch devices. The impedance mismatches, however, are fixed impedance transmission line mismatches and are not remote-controllable.
One of the objects of this invention is a highly efficient power controller which delivers virtually all of the input RF power to its output ports.
It is also an object of this invention to have a power efficient power controller which can be connected to a variable number of output ports.
Another object of this invention is a power controller which delivers power to several output ports and which can be easily adjusted to deliver no power to output ports that are turned off.
Yet another object of this invention is an efficient power controller which allows easy adjustment of the amount of power switched to any of its output ports.
Additional objects and advantages of this invention are set forth in the description which follows and in part would be obvious from that description or may be learned by practice of the invention. The objects and advantages of this invention may be realized by the apparatus pointed out in the appended claims.